Updated

The captain of a merchant ship bound for Singapore changed course for Australia this week for fear that desperate asylum seekers he had rescued in Indonesian waters would attack his crew, an official said Thursday.

Home Affairs Minister Jason Clare said the 67 would-be refugees could be deported to tent camps in the Pacific countries of Nauru or Papua New Guinea under new laws due to be passed by the Senate on Thursday aimed at deterring growing numbers of asylum seekers from attempting to make the dangerous journey to Australia by boat.

But the opposition has called for the asylum seekers to be charged with piracy for using threats to divert the 870-foot (265-meter) ship.

The asylum seekers were still near the main Indonesian island of Java in a crowded fishing boat headed for the Australian territory of Christmas Island, 250 miles (400 kilometers) to the south, when they made a distress call to Australian rescue authorities early Monday morning, Clare said.

The Australian authorities alerted all merchant shipping in the area, and Norwegian car carrier MV Parsifal was the first to respond.

Having fulfilled his obligation under maritime law to rescue the asylum seekers, the captain ordered his crew to continue to Singapore, the ship's intended destination.

"When the asylum seekers on the boat found out about this, they became very aggressive and the master of the ship made the decision to turn the vessel around and head to Christmas Island," Clare told Australian Broadcasting Corp. radio.

The captain, who has not been named, radioed the Australian Maritime Safety Authority to explain his decision.

"He made the point that he was concerned for his crew's safety and therefore decided to take the ship to Christmas Island," Clare said.

Clare said he did not have details of the behavior of the asylum seekers, reported by The West Australian newspaper to be Middle Eastern men.

But he was concerned that a ship's crew could feel threatened after rescuing seafarers in distress.

"It shows you just how dangerous it can be out on the high seas when you've got desperate people doing dangerous things," Clare said.

The asylum seekers were delivered to the immigration detention center on Christmas Island late Tuesday, hours after the government warned that any new boat arrivals could be sent to Nauru, a tiny atoll, or an island off Papua New Guinea, Australia's nearest neighbor, to have their refugee claims assessed.

The minor Greens party has condemned the plan as cruel.

The Australian Federal Police would not immediately say Thursday whether the asylum seekers were under criminal investigation.

Opposition immigration spokesman Scott Morrison described their apparent threat of violence toward their rescuers as "outrageous."

"They shouldn't be being assessed (as refugees), they should be being investigated for potential crimes of piracy that carries a life sentence under our Crimes Act," Morrison told reporters.

Prime Minister Julia Gillard declined to say whether the asylum seekers should be questioned by police.

"If anyone in any circumstance anywhere engages in unlawful conduct, then of course that unlawful conduct should be acted upon," she told reporters.

Australian National University international law professor Don Rothwell said Australia had jurisdiction to prosecute for an act of piracy anywhere in the world. He did not give an opinion on whether the asylum seekers' alleged conduct fit the legal definition of piracy.

Clare said military reconnaissance teams would fly to Papua New Guinea on Thursday and Nauru on Friday to plan the new detention camps. He expects the first asylum seekers to be sent to Nauru within a month, although an agreement has yet to be finalized with that country's government.

More than 7,600 asylum seekers -- many from war-torn countries, including Afghanistan, Iraq and Sri Lanka -- have reached Christmas Island in more than 100 boats so far this year.

A surge in boat arrivals and the deaths of more than 600 asylum seekers at sea in the past three years has prompted a tougher government stance.